Clinical and histological characteristics of poroid neoplasms: a study of 25 cases in Taiwan

Eyelid Eccrine Poroma: A Case Report and Literature Review

Eccrine poroma is a rare benign adnexal tumor arising from intradermal cells of eccrine sweat ducts. At least two-thirds of eccrine poromas present on the extremities, most commonly on the palms and soles. They are scarcely found on the face; to date, only 11 cases of eyelid poromas have been reported in PubMed. Biopsy excision with a free margin is necessary to distinguish it from malignant lesions and avoid recurrence with possible transformation to porocarcinoma. We present the case of a 23-year-old male with a histopathological confirmation of poroma using staining with hematoxylin-eosin on the eyelid, previously clinically diagnosed with molluscum contagiosum. After four years, he has not experienced a recurrence.

Poroid Hidradenoma: Case Report and Comprehensive Review of the Literature

Poroid hidradenoma (PH) is a rare benign adnexal tumor of eccrine differentiation. It is the rarest of the four described variants of poroid neoplasms. PHs characteristically share a hybrid of the architectural features of the hidradenoma, namely, tumor cells are entirely intradermal with both solid and cystic components, and the cytologic characteristics of the poroid neoplasms, containing predominantly poroid and cuticular cells. Many published reports of PH since its original discovery in 1990 state that "very few" cases of PH can be found in the literature. Here, we have identified a total of 75 published accounts of PH, including the case presented here, as well as the associated patient demographics, lesion characteristics, treatment, and outcomes. We suggest that while uncommon, PH is likely not exceptionally rare and could be an underreported diagnosis.

Dermal Duct Tumor: A Diagnostic Dilemma

Poromas or poroid tumors are a group of rare, benign cutaneous neoplasms derived from the terminal eccrine or apocrine sweat gland duct. There are four poroma variants with overlapping features: dermal duct tumor (DDT), eccrine poroma, hidroacanthoma simplex, and poroid hidradenoma, of which DDT is the least common. Clinically, the variants have a nonspecific appearance and present as solitary dome-shaped papules, plaques, or nodules. They can be indistinguishable from each other and a multitude of differential diagnoses, necessitating a better understanding of the characteristics that make the diagnosis of poroid neoplasms. However, there remains a paucity of information on these lesions, especially DDTs, given their infrequent occurrence. Herein, we review the literature on DDTs with an emphasis on epidemiology, pathogenesis, clinical features, diagnosis, and management.

Poroid hidradenoma of the scalp in a US Veteran's Administration (VA) patient

Poroid hidradenomas are a rare subtype of hidradenoma. A Veteran’s Administration patient presented with a mobile, cystic scalp lesion. Intraoperatively the mass spontaneously ruptured. We hope clinicians will consider this entity on their differential when treating patients presenting with similar scalp lesions and intraoperative findings.

Rare case of large eccrine poroma of the eyelid

Eccrine poroma is a rare tumor arising from sweat glands with common location being soles and palms. We are reporting a case of 70-year male patient with large lower lid mass lesion. Owing to its location and history of growth, malignancy was suspected. Biopsy proved it to be eccrine poroma which is a benign lesion. Complete excision with lid reconstruction was done. Eccrine poroma, though rare, should be kept in the differential diagnosis of eyelid tumors. Owing to the risk of malignant transformation and difficulty in clinical differentiation between poroma and porocarcinoma, wide excision should be done.

Eccrine poroma presented as spindle-shaped plaque: A case report

RATIONALE

Eccrine poroma, a benign cutaneous neoplasm originating from the intraepidermal portion of the eccrine sweat duct, is relatively common in clinical practice. Nevertheless, the 1 presenting as spindle-shaped plaque is extremely rare and easily misdiagnosed as seborrheic keratosis or other dermatoses. Thus, the current study demonstrates a case of eccrine poroma with unique clinical manifestation.

PATIENTS CONCERNS

A 47-year-old man presented with a spindle-shaped plaque on his left sole for 6 years.

DIAGNOSES

Based on the clinical and histopathological manifestations, diagnosis of eccrine poroma was established.

INTERVENTIONS

Surgical excision under local anesthesia was performed.

OUTCOMES

No recurrence or malignant transformation occurred within 6-month follow-up.

LESSONS

Eccrine poroma typically presents as a dome-shaped nodule on palm or sole. But this case reminded us the lesion presenting as a spindle-shaped plaque on sole can not rule out the possibility of eccrine poroma.

Eyelid Eccrine Poroma: A Case Report and Review of Literature

Poroma is a rare benign tumor of the epidermal sweat duct unit with predilection for the head and neck. Only six cases with eyelid location have been described in the literature (PubMed). A 34-year-old male presented with a single tumor on the left upper eyelid. It was skin-colored, nodular, solid, tender with some telangiectatic vessels, and showed no ulcerated lesion. Clinical diagnosis was basal cell carcinoma. This type of lesion can mimic a malignancy. Complete excisional biopsy revealed features consistent with eccrine poroma. After three year of follow up, no recurrence was observed. The authors reviewed all the cases reported in the literature and made a summary comparing them.

Clonal seborrheic keratosis: a rare skin tumor

Seborrheic keratosis is a benign epidermal neoplasm, representing one of the most common skin tumors. Clonal seborrheic keratosis is one of the histological subtypes of this entity. It is an uncommon lesion which may resemble other benign or malignant lesion. We report a case of a 60-year-old woman presented with a 7 year history of a gradually growing, cutaneous lesion on her left arm. On physical examination, the lesion was elevated, well-circumscribed, measuring 5 cm in maximum diameter. The tumor was biopsied. Histopathological examination revealed the presence of well-defined nests of clear-looking or basaloid keratinocytes within an acanthotic epidermis, corresponding to the Borst-Jadassohn phenomenon. The tumor cells were small and monomorphic. We diagnosed this tumor as clonal seborrheic keratosis. Although surgical excision was recommended, our patient refused an operation. This case of clonal seborrheic keratosis is presented for its rarity and for differential diagnosis.

Poroid hidradenoma in the hand: A case report and systematic review

Poroid hidradenoma (PH) is a rare benign neoplasm of the skin appendages. There are currently no guidelines for its management, and little information available regarding the natural history, treatment options, or outcomes. Systematic literature review identified 19 cases of isolated PH. Mean age at presentation was 54 years. Male to female ratio was 3:1, and the majority of cases were in the head and neck region. One-third of lesions were painful or tender. Sizes varied from 0.11 × 0.9 × 0.2 cm (digit) to 6 cm (presternal region). Twelve cases were treated by surgical excision, while the remainder were biopsy specimens. Follow-up was reported in five cases, with a median follow-up of 1 year. No cases of local invasion or spread have been reported, although there was one case of possible recurrence identified 8 years after surgical excision. The presented case is the first to identify a PH on the hand, represents the smallest lesion to date, and was successfully treated by excision. We suggest that PHs be treated by excision and followed up for 6 to 12 months. Given one case of potential (but unconfirmed) recurrence, and no report of malignant transformation, we suggest that narrow margins may be appropriate.

A Large Lumbar Adnexal Neoplasm Presenting Characteristics of Eccrine Poroma and Poroid Hidradenoma

Poroma is a rare benign neoplasm that derives from eccrine sweat glands epithelium. Its histological subtypes, with respect to its position within skin layers, are eccrine poroma, hidroacanthoma simplex, poroid hidradenoma, and dermal duct tumor. Poromas commonly exhibit benign clinical behavior as they are usually small and asymptomatic and do not exhibit malignant behavior. Although their histological subtypes share similar histological characteristics, they rarely coexist in the same tumor. In this report we present the case of an unusual poroma in terms of histological and clinical behavior as it was large and presented histological characteristic of both eccrine poroma and poroid hidradenoma. Coexistence of different histologic subtypes in the same tumor indicates simultaneous tumorigenesis, differentiation from one cell type to another, or parallel differentiation from a common progenitor cell. Implications in treatment remain unknown partly due to the rarity of such cases.

Topics in histopathology of sweat gland and sebaceous neoplasms

This article reviews several topics regarding sweat gland and sebaceous neoplasms. First, the clinicopathological characteristics of poroid neoplasms are summarized. It was recently reported that one-fourth of poroid neoplasms are composite tumors and one-fourth are apocrine type lesions. Recent progress in the immunohistochemical diagnosis of sweat gland neoplasms is also reviewed. CD117 can help to distinguish sweat gland or sebaceous tumors from other non-Merkel cell epithelial tumors of the skin. For immunohistochemical differential diagnosis between sweat gland carcinoma (SGC) other than primary cutanesous apocrine carcinoma and skin metastasis of breast carcinoma (SMBC), a panel of antibodies may be useful, including p63 (SGC⁺ , SMBC^- ), CK5/6 (SGC⁺ , SMBC^- ), podoplanin (SGC⁺ , SMBC^- ) and mammaglobin (SGC^- , SMBC⁺ ). Comparison of antibodies used for immunohistochemical diagnosis of sebaceous carcinoma (SC) suggests that adipophilin has the highest sensitivity and specificity. Some authors have found that immunostaining for survivin, androgen receptor and ZEB2/SIP1 has prognostic value for ocular SC, but not extraocular SC. In situ SC is rare, especially extraocular SC, but there have been several recent reports that actinic keratosis and Bowen's disease are the source of invasive SC. Finally, based on recent reports, classification of sebaceous neoplasms into three categories is proposed, which are sebaceoma (a benign neoplasm with well-defined architecture and no atypia), borderline sebaceous neoplasm (low-grade SC; an intermediate tumor with well-defined architecture and nuclear atypia) and SC (a malignant tumor with invasive growth and evident nuclear atypia).

Clear cell proliferations of the skin

Clear cell proliferations of the skin consist of a diverse group of lesions characterized by the presence of cells with abundant clear cytoplasm. They may arise from primary, metastatic, or non-neoplastic origins, with their distinctive cytoplasmic clearing attributable to causes ranging from artifact to accumulation of materials such as glycogen, mucin, or lipids. Despite the heterogeneity of these lesions, their distinguishing characteristics may be subtle, especially at high power. As such, histologic diagnosis can be challenging, and proper consideration relies on an understanding of the scope of possible origins, etiologies, and key immunohistochemical staining patterns of the various entities. This review categorizes cutaneous clear cell neoplasms by histogenesis, and offers differential diagnostic strategies to aid in their clinicopathologic evaluation.

Pedunculated poroma on forearm: A rare clinical presentation

Eccrine poroma (EP) is an adnexal tumor that commonly occurs on soles as a soft sessile flesh colored nodule. We report here a case of 54-year-old man who presented with a pedunculated red colored nodule on the right forearm. Histopathological examination was consistent with EP. This presentation of EP on the forearm as a pedunculated nodule is rare.

Eccrine poromatosis: case report and review of the literature

Eccrine poroma (EP) is a benign tumor of the eccrine duct. Multiple EPs are defined as eccrine poromatosis (EPS), an uncommon phenomenon. To date there are only eight reported cases of EPS. This review exemplifies the epidemiology, pathogenesis, differential diagnosis, and histology of EP, while reviewing the eight cases of EPS. Six of the eight cases of EPS had a history of immunosuppression from either radiation or chemotherapy. This paper will also emphasize the importance of excision to avoid possible malignancy. Here we present a 73-year-old gentleman with EPS who was also treated with radiation and chemotherapy prior to the onset of the lesions.

Unusual sites for poromas are not very unusual: a survey of 101 cases

BACKGROUND

Poromas are benign adnexal tumours generally believed to be of eccrine origin, which usually develop on palmoplantar sites. However, it is thought that a percentage of poromas develop on non-palmoplantar or 'unusual' sites.

AIM

To review cases of poromas with reference to their clinicoepidemiological characteristics, paying particular attention to the those located on sites other than the palms and soles.

METHODS

All histologically confirmed poromas seen at our department between 1994 to 2012 were reviewed. The clinicoepidemiological data recorded included age at diagnosis, gender, location, size, colour, and preoperative and pathological diagnoses.

RESULTS

In total, 101 poromas were reviewed, corresponding to 0.0058% of all the epithelial skin tumours biopsied in our department. The mean age was 65.05 years (range 30-100 years), and the male to female ratio was 1.52. All the lesions were solitary and asymptomatic, with no sign of bleeding. The most common presentation was a red or reddish lesion, particularly at palmoplantar sites, where 33 (32.7%) of the 101 poromas were located, Poromas found at other affected sites were more usually skin-coloured, and these lesions included 7 neoplasms located in the armpits and 18 on the head and neck. The correct preoperative diagnosis was made in 12 cases of 33 detected poromas (36%), all of which were localized to the palmoplantar surfaces.

CONCLUSIONS

Based on our experience, we consider that there are no 'unusual' sites for poromas, and palmoplantar poromas were in fact in the minority. Furthermore, some localizations suggest derivation of these palmoplantar poromas from the folliculosebaceous apocrine unit.

Benign acquired superficial skin lesions of the hand

Numerous dermatologic conditions may be visualized by the hand surgeon during office hours, including when examining patients for an alternative chief problem. Although the primary focus of the visit may be unrelated to a skin lesion, it is important for the hand surgeon to be familiar with these lesions to address patient inquiries and determine which lesions may require some form of treatment. This article reviews some of the most common benign acquired superficial skin lesions of the hand. Particular attention will be paid to epidermal lesions, pigmented lesions, vascular lesions, dermal fibrous/fibrohistiocytic lesions, and infections that can be confused with skin neoplasms or tumor-like conditions. Diagnostic clues, including photographs, will be provided for each lesion described, as well as the recommended treatment.

Poroid hidradenoma in a child: an unusual presentation

Poroid neoplasm is a benign sweat gland neoplasm that accounts for 10% of sudoriferous tumors. Poroid hidradenoma is an uncommon variant that usually affects adults, with a peak of incidence in the seventh decade. It is rare in children. We report the first case of poroid hidradenoma presenting in a 13-year-old boy.

A single lesion showing features of pigmented eccrine poroma and poroid hidradenoma

Poroid hidradenoma (PH) is a variant of poroma. This entity was defined by Abenoza and Ackerman in 1990. This neoplasm shows architectural characteristics of hidradenoma (tumor cells confined entirely within the dermis in both solid and cystic components) and cytologic characteristics of poroid neoplasm (poroid and cuticular cells, the latter showing ductal differentiation). We herein document a case of single poroid lesion with the features of both eccrine poroma and PH. The patient was a 55-year-old woman with a pigmented nodular lesion on her upper back for 7 years. The histopathologic features of the lesion were consistent with those of eccrine poroma and PH. Unlike most eccrine poromas, this case was pigmented, clinically and microscopically.

Poroma of the eyelid

A 71-year-old white woman sought treatment for poroma of the right lower eyelid. Excisional biopsy was performed, and the specimen had histologic features consistent with poroma. One year after excision, there has been no recurrence of the lesion. Clinicians should be aware that poroma can occur in regions other than the hands and feet.

Histopathological and immunohistochemical studies of poroid hidradenoma

Poroid hidradenoma (PH), a less common subtype of poroid neoplasm (PN) than eccrine poroma (EP), has not been immunohistochemically studied before. Six cases of PH (four solitary PH and two PH coexisted with other types of PN) were included in the study. Fifteen cases of EP were also included for comparison. Hematoxylin and eosin, Masson-Zimmerman silver stain, and a variety of immunohistochemical stains were used. Microscopically, PH is not connected to the epidermis. All six PH contained small poroid cells and larger, paler cuticular cells. Some PH showed separate or clusters of sebocytes (2/6), horn cysts (1/6), juxtaposed lymphoid follicles in the stroma (1/6) and foci of keratohyaline granules (2/6), none of which was seen in the 15 EP. Immunohistochemically, the keratin distribution of PH was very similar to that of EP. PH has a very small number of Langerhans cells (significantly lower than the overlying epidermis, P=0.045), and a sparse deposition of melanin. We conclude that except the location, the histopathological and immunochemical differences between PH and EP were small. Sebaceous differentiation in two PH lesions suggested the possibility of an apocrine origin. The deeper parts of eccrine apparatus other than basaloid cells may have been more actively involved in the histogenesis of PH.